Carbureter.



Patented Oct. 3,1916.

2 SHEETS-SHEET I.

INVENTOR Jase M1 C. Cou/omle Afro/mu J. C. COULOMBE.

CARBURETER.

TIZI

WITNESSES:

1. c. COULOMBE.

CARBURETER. APPLICATION FILED JULY 25.1913.

Patented Oct. 3,1916.

. 2 SHEETS-SHEET *2.

l/VVE/VTOI? (7568 06 cau/ome WITNESSES S A TTOR/VEY UNITED STATES PATENT OFFICE.

JOSEPH C. COULOMBE, 0F KEENE, NEW HAMPSHIRE, ASSIGNOR, BY MESNE ASSIGN- MENTS, TO BLAN CHE D. COULQMBE, OF KEENE, NEW HAMPSHIRE.

CARBURETER.

Specification of Letters Patent.

Patented Oct. 3, 1916.

Application filed July 25, 1913. Serial No. 781,126.

.Carbureters, of which the following is a full, clear, and exact description, whereby any one skilled in the art may make and use the same.

The invention relates to carbureters and particularly to the class of devices which are commonly employed for vaporizing fluids to provide an explosive mixture for internal combustion engines.

. The object of the invention is to provide a device of the character referred to which, throughout the varying speeds of the engine and consequent variations in suction, will produce a mixture of definite and proper richness.

A further object is to provide a carhureter in which the richness of the mixture will remain constantly correct even under subjection to variations in altitude or changes in atmospheric pressure.

It is also an object of the invention to maintain an explosive mixture of proper character at all times even under wide ranges in the change of temperature.

Carbureters, so-called, are very commonly known in the art and include the simplest types of devices such as the wellknown mixing valve and the more refined types commonly referred to as float feed carbureters and constant level carbureters. In these devices it is a general practice to maintain aconstant level in the float feed chamber and the aspirating nozzle which is arranged appurtenant to the in-take or. inlet of the carbureter.

Many types of adjusting devices are in common use for attempting to maintain a constant mixture of the fuel and air during the widely varying range occasioned by the increasing and decreasing suction of the engine due to variations in speed. Such adjusting devices include means for varying the suction effect at the nozzle and means for introducing additional air through an auxiliary air valve which is automatically controlled. In all such devices, so far as known, there is more or less an element of error in the exactness of the mixture under the very great variations of conditions to whlch such a device is subjected. Variations in atmospheric condition, that is, heat and cold, destroy the eflicacy'of adjustments J which, under constant temperature conditions, might be perfect enough for all practical purposes. Variations in altitude greatly .disturb the adjustment and cause the variation in feed of the fuel which often requires a complete re-adjustment of the mechanism to secure a proper richness of the mixture.

The principal object of the invention herein defined is toovercome as far as possible such objections by maintaining under all conditions a constant, natural flow of fuel to the nozzle which will give a constant mixture of proper character upon varying engine speeds and consequent engine suction upon wide ranges of change in temperature and even with changes in altitude.

Referring to the drawings: Figure 1 is a central vertical section through the device. Fig. 2 is a cross-sectional view on the line 2-2 of Fig. 1. Fig. 3 illustrates the mechanism of Fig. l with a modified form of auxiliary air valve. Fig. 4 is a cross-sectional view on the line 4-4 of Fig. 3.

In order to accomplish the results heretofore enumerated, the device hereinafter described embodies a float feed chamber in which a float automatically maintains a definite level of the liquid fuel to be vaporized. This float feed chamber is operatively arranged with reference to a nozzle which is adjusted to substantially the same level as that of the fuel in the float feed chamber. Intermediate the float feed chamber and the nozzle is a chamber which has a variable the float feed chamber and the variable level chamber are open to and subjected to the same conditionsof atmospheric pressure and a valve which is actuated by the varying' conditions of suction or vacuum in the carbureter controls the flow of fluid from perature will cause variations in the valve opening and consequently vary the volume of fluid passed from the float feed chamber into the variable level chamber. In the drawings, there is illustrated a form of device for carrying out the purposes enumerated, although it is of course apparent that the form and arrangement of parts might be materially changed and varied to suit the exigencies of any particular requirement.

Referring to the drawings, the numeral 1 indicates a casing of any suitable form having a main air inlet 2 and an outlet 3, the latter controlled in any desired manner as by a butterfly valve 4 which serves as a throttle for controlling the flow of explosive mixture from the carbureter to the engine, the cylinders of which are connected with the outlet side. 3 of the carbureter. Within the casing 1 there is arranged a float feed chamber 5 having a fuel inlet 6 controlled by a valve 7 which is raised and lowered with reference to its seat by a float 8. connected with the valve spindle through a suitable lever 9.

As illustrated in the drawings, the float feed chamber 5 has centrally arranged with reference-to it and its float 8 a tubular chamber 10. This chamber has an inlet opening 11 coincident with its lower end and the bottom of the float feed chamber and at a slight distance above said opening, there is a valve opening 12 which is controlled by a suitable valve herein shown as a needle valve 13. It will be noted that the valve opening 12 is arranged at a definite distance above the bottom of the float feed chamber and also at a definite distance below the level of the fuel in said chamber. Connecting with the variable level chamber 10 is a duct or passage 14 which terminates in a nozzle. 15, said nozzle being arranged at a height substantially equal to or slightly above the level of fluid in the float feed chamber. This nozzle 15 projects up into the'air inlet 2 and, as illustrated, is centrally arranged with reference to the slightly contracted walls 16 thereof. Perforations 17 and 18 or any suitable openings subject the fluid in the float feed chamber and the variable level chamber to the same atmospheric pressures and conditions. The needle valve 13 controlling the inlet valve opening 12 may vary its position in conjunction with variations in the suction produced by the engine.

As illustrated in the drawings, an auxiliary air valve 19 normally pressed to its seat 20 by a spring 21, has a tubular stem 22 which has a sliding fit in a spring adjusting gland 23. The stem of the needle valve 18 is threaded and may be adjusted axially of the sleeve 22. This auxiliary air valve 20 will raise under conditions of undue suction and will, in turn, raise the needle valve 13, permitting an enlarged opening for the passage of fluid from the float chamber into the variable level chamber. The valve 13 is preferably formed of a material di fler ing in its characteristics from the material of the valve seat 12. That is, it is formed of a ductile material having a high coefficient of expansion as compared with the material of the valve seat. Thus it is made susceptible to variations in temperature and be ing of the needle type will restrict or open the opening to a greater or less extent to permit a greater or lesser flow of fuel to the inlet opening 12. With this' arrangement of parts it is obvious that a constant level of fluid is maintained in, the float feed chamber and the level in the variable level chamber 10 will be varied to a greater or lesser extent dependent upon the suction at the nozzle and the quantity of fluid passed through the inlet 12 to said variable chamber.

When the engine is first started, the level of the fuel in the variable level chamber is decreased to a point below the inlet 12 and this chamber bein open to atmosphere there is a constant ow of fluid under gravity from ,the float feed chamber through the inlet 12 inasmuch as both chambers are subjected to the same atmospheric pressure and there can be no variation due to variations in the suction inasmuch as when the level of the chamber 10 has fallen below the inlet 12, there is a constant flow of fluid due to the difference in height between the level of the fuel in the float feed chamber 5 and the flxed level of the inlet 12. Obviously, the varying suction from the nozzle 15 will have no effect upon the constancy of the flow from the float feed chamber into the variable level chamber 10. It is also apparent that the volume of the flow is governed by the difference in the constant level'of the float feed chamber and the difference in level of the inlet 12 of the variable level chamber. Naturally, after the engine is in operation, the difference in level is a constant being the difference in height between the inlet 12 and the constant level of the fluid in the float feed chamber. As the engine speed increases. and induces a greater suction and more air is passed through the inlet 2, if the opening of the valve 13 remained constant, the mixture would become weaker and weaker. To compensate for this, the tapered needle valve is arranged to be raised by the valve 19 and the greater the suction, the greater will be the opening at the inlet 12 and consequently there will be a greater flow of fluid, simply under gravity to said opening in proper proportion to the increased flow of air. As the atmospheric pressure in the float feed chamber and the auxiliary variable level chamber are the same under all atmospheric conditions, the quantity of fluid flowing through the inlet 12, will remain a constant -be the flow of fluid. Vice-versa increases in temperature will restrict the opening and consequent flow. Various materials may be used for securing this differential adjustment of the opening. For instance, the body of the device and its valve seat may be composed of brass and the tapered valve of aluminum or aluminum. alloys. This gives very good results and obviously the changes may be made very delicate by utilizing materials having wide differences of variations in their respective co-efiicients of expansion.

In Figs. 3 and 4: there is shown a slightly modified arrangement of auxiliary air valve. In these figures the float feed 25 actuates levers 26 which raise or depress the valve stem 27 that controls the fuel inlet 28 to the float feed chamber 29. The nozzle 30 is arranged at or slightly above the level of the fluid in the float feed chamber and connects with the auxiliary variable level chamber 31. This chamber has an inlet 32 at the bottom of the float feed chamber and a valve seat 33 below the level of the fluid of the float feed chamber. is controlled by a needle valve 34: which is threaded to adjustably engage a boss 35 arranged upon a supporting fork 36 which projects through an opening 37 in the wall of the chamber 31 and engages a groove 38 circumferentially arranged in a choke-tube 39. The valve spindle 40 of theneedle valve 34 passes through a spring adjusting gland 41 which gland bears upon the upper end of an adjustin spring 42, the lower end of said spring bearing upon the boss 35. The action of flow between the float feed chamber 29 and the nozzle is identical with the case heretofore described in connectionwith Figs. 1 and 2. The only difference in the arrangement is in that of the choke-tube 39 which, as the engine speeds up and creates an increasing suction, raises above the nozzle 30 and in turn opens the needle valve 34,

. giving a larger orifice for the flow of fuel from the float feed chamber to the nozzle.

Obviously, the arrangement of parts might be modified in almost any number of designs to suit any particular application of the device without departing from the spirit or ntent of the invention so long as the arrangement contains a float feed chamber and auxiliary variable level chamber and means for securing a constant flow under the action of gravity for any given valve opening irrespective of the suction at which employ a float feed chamber, an

aspirating nozzle and a chamber intermediate the aspirating. nozzle and float feed chamber with no means of automatically regulating the opening between the float feed chamber and intermediate variable level chamber nor should it be confounded with the device embodying the above elements and the additional element of a second aspirating nozzle arranged in the inlet air tube and connecting directly with the float feed chamber.

In the device herein described, the float feed of the float chamber maintaining a constant level therein, and the outlet 12, to the constant level chamber 10, being arranged at a definite position below the level of the fluid in the float chamber, there will be a constant flow under a constant head at all times when the device is in operation. Of course, the volume of the flow will vary as the valve 13 varies its position. Its variations are dependent upon the suction of the engine and the position of the auxiliary air valve 20. This arrangement will always maintain a balance between the volume of liquid fuel and air, which will give a mixture of proper character for all speed Variations under all variable conditions due to altitude or atmospheric changes or, in fact, changes of temperature.

What I claim as my invention and desire to secure by Letters Patent is:

1. In a carbureter, the combination of a single suction controlled fuel feed nozzle and a float feed chamber having a flow under constant head to the nozzle which flow is uninfluenced by the suction at the nozzle and means including an automatically actuated valve for varying the volume of the flow from the float feed chamber upon variations in suction ofthe engine upon the carbureter.

2. In a carbureter, the combination of a suction controlled fuel feed nozzle, a variable level chamber connected therewith, a-

constant level fuel'chamber connected with the variable level chamber, said chambers being open to the atmosphere to provide a flow under constant head from one to the other, said flow being uninfluenced by the flow from the constant level fuel chamber' under constant head.

3. In a carbureter in combination, a float level of the float feed chamber, a nozzle connected with said variable level chamber and arranged in the air inlet of the carbureter and a suction controlled valve for varying the opening of the inlet to the variable level chamber. M

4. In a carbureter in combination, a float feed chamber having means for maintaining a constant level of fuel, a variable level chamber having an inlet below the fluid level of the float feed chamber, a valve actuated by the suction induced in the carbureter for varying the volume of flow from the float feed chamber to the variable level chamber, a nozzle connected with the variable level chamber and arranged in the air 5. In a carbureter, the combination of a float feed chamber having means for maintaining a constant level of fuel, a variable level chamber connected therewith, both said chamber and the float feed chamber being open to atmospheric pressure, an aspirating nozzle arranged in the air inlet of the carbureter for delivering fuel without influencing the pressures in the variable 'level chamber and a valve controlling the flow of fuel from the float feed chamber to the variable level chamber, said valve beng actuated by a valve controlling an auxlliary air inlet to the carbureter.

JOSEPH C. COULOMBE.

Witnesses KATE BRENNER, FRANCIS Comrrr. 

